Tesla Model 3: Elon Musk Explains High Safety Score With Ice Skater Analogy

The Tesla Model 3 could rank as one of the safest cars ever under the National Highway Traffic Safety Administration’s tests, thanks to the laws of physics. The agency announced on Friday that the $35,000 electric car scored full marks in all safety tests. CEO Elon Musk said on Twitter that its electric car design, with the heavy batteries under the car and an empty front trunk, “helps improve forward crumple zone length, especially important in high-speed frontal impacts, and moments of inertia in side impacts.”

“Key technical point is that the polar moment of inertia (concentration of mass around center) of a Tesla, to the extent of our knowledge, is better than any other production car,” Musk wrote on Twitter. “This positively affects safety, handling & driving feel. Extremely important metric…front vs rear wheel weight distribution, though commonly asked, isn’t the right question. You can have 50% on front, 50% on rear & still have poor handling if mass elements are far from center. Dumbbell mass distribution is bad, spinning top/dreidel is good.”

See more: Elon Musk Shares Tesla Model 3’s Perfect NHTSA Safety Rating

Musk shared a link to an article detailing polar moment of inertia, which explains why it’s important to keep the weightiest parts of a vehicle as close to the center of gravity as possible. Musk likened the phenomenon to “an ice skater. Same weight, but spins/turns much faster with arms in vs arms out. Same principle is true for a car.”

The NHTSA gave the Model 3 a five-star safety rating in every category. The agency tested the car under simulations of a crash with two cars moving at 35 mph, a collision between a barrier and car at 38.5 mph, and a crash into a fixed object. Like the Model X and S beforehand, the car scored full marks in all these areas.

Musk promised that Tesla will publish a more detailed explanation of the car’s high safety record soon. The NHTSA is also expected to publish more detailed statistics soon.

Tesla has made a habit of highlighting its cars’ high safety values. At the July 2017 Model 3 handover event, Musk showed a video of a Model 3 crash compared to the Volvo S60.